Photon-counting detectors for computed tomography enable the generation of spectrally resolved computed tomography medical image data. A photon-counting detector can be configured to acquire x-ray projection data in a plurality on energy bins. For example, four energy bins can be used to cover the whole range of energies of the acquired x-ray projection data. The photon-counting spectral computed tomography data related to the plurality of energy bins can be used to calculate blended images, material decompositions and/or virtual mono-energetic images.
The window parameters of the energy bins may be pre-defined before the start of the acquisition of the x-ray projection data. In a basic approach, the same pre-defined window parameters of the energy bins are used for different kinds of computed tomography applications, without adaption to the specific structure and/or tissue under examination. To improve the quality of the acquired photon-counting spectral computed tomography data, the window parameters of the energy bins may be adapted with regard to the specific computed tomography application. Various methods for providing optimized window parameters of the energy bins have been proposed (see documents [1]-[5] in the Bibliography at the end of the specification).